Annexin V Staining
Annexin V Staining - Related Videos
09:09
Annexin V and Propidium Iodide Labeling
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2023
Staining with annexin V and propidium iodide (PI) provides researchers with a way to identify different types of cell death—either necrosis or apoptosis. This technique relies on two components. The first, annexin V, is a protein that binds certain phospholipids called phosphatidylserines, which normally occur only in the inner, cytoplasm-facing leaflet of a cell’s membrane, but become “flipped” to the outer leaflet during the early stages of apoptosis. The second component is the DNA-binding...
04:21
Annexin V Binding Assay: A Fluorescence-Based Technique to Identify Apoptotic Erythrocytes via Phosphatidylserine Labeling
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2025
In this video, we demonstrate the Annexin V binding assay to measure the degree of eryptosis, erythrocyte programmed cell death, using fluorescent Annexin V staining. Apoptotic erythrocytes demonstrate phosphatidylserine translocation from the inner to the outer leaflet of the cell membrane, causing the fluorophore-tagged Annexin V to bind to the translocated phosphatidylserine, thereby emitting a fluorescent signal.
07:34
Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death
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Cited by 543 •
2011
An accurate method for the assessment of cell death is described. The protocol improves upon conventional Annexin V/ propidium iodide (PI) protocols, which display up to 40% false- positive events in cell lines and primary cells from a broad range of animal models.
11:33
Microscopy and Staining: Gram, Capsule, and Endospore Staining
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2023
Source: Rhiannon M. LeVeque1, Natalia Martin1, Andrew J. Van Alst1, and Victor J. DiRita1 1 Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America Bacteria are diverse microorganisms found nearly everywhere on Earth. Many properties help distinguish them from each other, including but not limited to Gram-staining type, shape and arrangement, production of capsule, and formation of spores. To observe these properties, one...
03:12
May-Grunwald Giemsa Staining: A Method to Stain Bone Marrow Cells
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2023
This video describes the technique of staining bone marrow cells using May- Grünwald Giemsa Staining. In the protocol, we will stain the murine myeloid leukemia cells, C149 cells, to analyze the morphology and differential counting.
FAQs
Calcium ions enable fluorescently labeled Annexin V to bind selectively to phosphatidylserine exposed on the cell surface. Without this calcium-dependent interaction, the signal would not reliably indicate phosphatidylserine exposure. Maintaining the required calcium presence is therefore central to interpreting fluorescence as evidence of an apoptosis-associated membrane change rather than as a nonspecific labeling event.
Propidium iodide adds information about plasma-membrane integrity because it is membrane-impermeable. When used with Annexin V, the two signals help separate viable cells from cells showing early apoptosis, late apoptosis, or necrosis. This combination provides a more informative cell-state profile than Annexin V fluorescence alone, particularly when a treatment produces several overlapping forms of cell injury.
Both approaches detect fluorescence from labeled Annexin V, but they provide different views of the result. Fluorescence microscopy allows researchers to examine labeled cells directly, whereas flow cytometry supports analysis of cell populations based on their fluorescence signals. The choice depends on whether the study emphasizes visual cell-level assessment or rapid population-level measurement.
The method distinguishes cell states by combining phosphatidylserine exposure with membrane permeability. Cells without the relevant signals are interpreted as viable, Annexin V-positive cells with preserved membrane exclusion as early apoptotic, and cells positive for both Annexin V and the membrane-impermeable dye as late apoptotic or necrotic. These categories help track progression rather than recording apoptosis as a single endpoint.
A typical workflow labels cells with fluorescent Annexin V in the presence of calcium ions, optionally adds propidium iodide or another membrane-impermeable dye, and then examines the resulting fluorescence by microscopy or flow cytometry. Researchers interpret the combined signals to assign cell states. The workflow can therefore provide a rapid snapshot of treatment-related changes in a cell population.
Researchers choose this assay when they need to measure changes associated with programmed cell death or evaluate how cells respond to a treatment. It is especially useful for assessing cytotoxicity and drug responses because the combined fluorescence pattern can reveal shifts among viable, early apoptotic, late apoptotic, and necrotic populations rather than only overall loss of cell survival.
Annexin V staining supports investigations of programmed cell death, cytotoxic effects, drug responses, development, and disease mechanisms. By measuring changes in cell-state distributions, it can help connect an experimental condition with altered apoptosis-related behavior. In biology, the assay is therefore useful for comparing cellular responses across treatments or contexts while distinguishing early changes from later membrane damage.